The Shoulder Anatomy

Bones 4 Articulations – AC, GH, SC, and Sub Ac Glenoid Labrum – fibrocartilagenous rim of glenoid fossa 50% of socket provided by Labrum

Capsule Glenoid margin to humeral anatomical neck Lax Lined with synovial membrane Becomes weaker with age Coracohumeral ligament – broad thickening of upper capsule

Ligaments Superior, middle and inferior Glenohumeral Ligaments Coracoacromial - forms the coracoacromial arch Transverse humeral

Anterior Scapula Muscle Attachments

Posterior Scapula Muscle Attachments

Anterior Musculature Supraspinatus Subscapularis Biceps Coracobrachialis Pectoralis Major and Minor Deltoid

Posterior Musculature Infraspinatus Teres Minor Triceps

Rotator Cuff Reduces AP shearing Subscapularis most powerful Inferior rotator cuff controls centring of the humeral head in elevation Infraspin. Subscap. Teres minor

Bursa Main pain generators of shoulder? Subscapula bursa – communicates with capsule Subacromial bursa – facilitates movt between coracoacromial arch + subjacent supraspinatus + shoulder joint

Neurology Supplied by C5 C4 AC joint Dermatomes C4 top of shoulder C5 lat asp of arm to wrist Muscles C5 Deltoid, supraspinatus, infraspinatus C6 Biceps, Subscapularis C7 Triceps, Lat Dorsi, Pec Major, Teres Major

Surface Markings Supraspinatus insertion Subscapularis insertion Infraspinatus insertion Acromion Coracoid AC joint line – sagital plane